I'm chiming in here to more or less echo glowfast. I have a mini telemaster I've been flying for about a year on a plain old run-of-the-mill speed 400 geared 2.3:1 with 8 cells and an 8x6 sloflyer prop. That works out to roughly 15 oz. of thrust at 100w in, about 65w out. This plane has more than adequate climb and can do multiple loops from level flight on this power setup. Fancy B/L motors need not apply. I think a Norvel .061 will be more than sufficient for a conversion here. I was thinking about it with an OS .10, but found another home for the OS before I finished up the airframe. I would hesitate to go big on the motor because of the lightweight nature of the airframe--it wouldn't take too much to overspeed and cause structural failure, IMO. One suggestion for building, either increase the dihedral, or do as I did and add about 3/8" to the rear of the rudder. The plane could use more turning authority than the stock design gives it--I might add here that mine snap rolls nicely with the added rudder.